For the long term free submission could be a good strategy on 2-3 years you get some good links. I am just too picky where I have my links from to use then.
I will submit to 'good' (if I know the owner or if I see a custom or customized template or a nice logo and some mods, anything to show me the owner has put a little bit of thought and effort into their project) free directories and generally buy a featured link also if they are reasonably priced and the owner approves my free link submissions.